* {
  box-sizing: border-box;
}
p {
  margin: 0;
}
input, button {
  border: none;
  outline: none;
}
a {
  text-decoration: none;
}
ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
pre {
  white-space: pre-line;
  word-break: break-all;//换行
}